The rath at Lackan in County Galway is more elaborate than that. Sitting in level pastureland, it presents three concentric banks of earth and stone, each separated by its own fosse, the term for the ditches dug to accompany such earthworks. The overall circuit spans roughly sixty metres across, and the whole interior is now colonised by trees and scrub, giving the monument a dense, enclosed quality quite different from the open, cropped ringforts found on higher or more exposed ground.

The structure belongs to a category sometimes called a multivallate rath, the additional banks and ditches generally interpreted as marking higher social status, greater defensive concern, or both. Scholarly attention came early: T. J. Westropp noted the site in 1919, observing that the causewayed entrance gap on the eastern side, just two and a half metres wide, appeared to be a relatively modern insertion rather than an original feature of the design. McCaffrey catalogued it again in 1952. Beneath the uneven interior surface lie two souterrains, underground stone-lined passages that would have served the original occupants as storage spaces or places of refuge. Their presence alongside the multiple enclosing banks adds to the sense that whoever held this site invested considerable effort in its construction and maintenance.